Abstract: A corner structure of a liquefied gas storage tank is provided, wherein the corner structure is installed at a corner of the storage tank for storing liquefied gas to support sealing walls. The corner structure includes: a stationary member secured to an inner surface of a hull structure wall; a movable member disposed on the stationary member such that the sealing walls are joined thereto; and an insulating member interposed between the sealing walls and the hull structure wall. The stationary member includes a stationary member body bent at a curved portion thereof in an opposite direction to the movable member, and the movable member includes a movable member body bent at a bent portion thereof in an opposite direction to the stationary member. The stationary member and the movable member are coupled to each other by a fastening member that penetrates the curved portion and the bent portion.

Abstract: An apparatus and a method for determining a Channel Quality Indicator (CQI) using a beamforming in a multi-antenna system are provided. A transmitter for determining a CQI based at least partly upon the beamforming in the multi-antenna system includes a beam former for distinguishing frequency tone intervals having a constant channel across an entire frequency tone, forming a beam by multiplying frequency tones of the frequency tone interval having the constant channel by different beamforming weights, and transmitting a preamble signal. Hence, the users can be scheduled based at least partly upon the beamforming gain, and throughput can be enhanced through the practical MCS selection.

Abstract: An apparatus and method for beamforming in a communication system are provided, in which a base station receives a channel vector from each of a plurality of mobile stations, generates an uplink channel matrix using the received channel vectors, generates a beamforming weight vector using the uplink channel matrix and a fixed constant that minimizes a channel error rate, and forms beams using the beamforming weight vector.

Abstract: Provided is an apparatus and method for determining a transmission mode for a base station in a wireless mobile communication system. The method includes measuring a state of a channel with a mobile station, determining whether channel states between the mobile station and a predetermined number of other mobile stations are orthogonal to each another, determining a space division multiple access (SDMA) mode as the transmission mode for the base station if the channel states are orthogonal to each other, and determining a beamforming (BF) mode as the transmission mode for the base station if the channel states are not orthogonal to each other.

Abstract: An apparatus and method for channel estimation in a wireless communication system are provided. The apparatus includes a Channel Quality Indicator (CQI) memory unit for collecting a predetermined number of pieces of channel information for two or more mobile stations (MSs), a CQI DIFference (CQIDIF) memory unit for storing a predetermined number of differences between consecutive pieces of channel information with respect to each MS, a CQIDIF dispersion unit for calculating a predetermined number of dispersions between two pieces of consecutive channel information with respect to each MS, and a second comparator for comparing a dispersion for differences between the two consecutive pieces of channel information with a second threshold to identify a Rician channel.

Abstract: Provided is an apparatus and method for canceling interference by a base station in a wireless mobile communication system. The method includes measuring a state of a channel with a mobile station, determining metric function values for channels that act as interference to the channel of the mobile station, selecting a predetermined number of interference channels in descending order of the metric function values, determining a weight vector for removing a signal transmitted over the interference channels, and applying the determined weight vector to a transmission signal and transmitting the weight vector applied signal.

Abstract: An apparatus and a method for determining a Channel Quality Indicator (CQI) using a beamforming in a multi-antenna system are provided. A transmitter for determining a CQI based at least partly upon the beamforming in the multi-antenna system includes a beam former for distinguishing frequency tone intervals having a constant channel across an entire frequency tone, forming a beam by multiplying frequency tones of the frequency tone interval having the constant channel by different beamforming weights, and transmitting a preamble signal. Hence, the users can be scheduled based at least partly upon the beamforming gain, and throughput can be enhanced through the practical MCS selection.

Abstract: An apparatus and method for channel estimation in a wireless communication system are provided. The apparatus includes a Channel Quality Indicator (CQI) memory unit for collecting a predetermined number of pieces of channel information for two or more mobile stations (MSs), a CQI DIFference (CQIDIF) memory unit for storing a predetermined number of differences between consecutive pieces of channel information with respect to each MS, a CQIDIF dispersion unit for calculating a predetermined number of dispersions between two pieces of consecutive channel information with respect to each MS, and a second comparator for comparing a dispersion for differences between the two consecutive pieces of channel information with a second threshold to identify a Rician channel.

Abstract: Provided is an apparatus and method for determining a transmission mode for a base station in a wireless mobile communication system. The method includes measuring a state of a channel with a mobile station, determining whether channel states between the mobile station and a predetermined number of other mobile stations are orthogonal to each another, determining a space division multiple access (SDMA) mode as the transmission mode for the base station if the channel states are orthogonal to each other, and determining a beamforming (BF) mode as the transmission mode for the base station if the channel states are not orthogonal to each other.

Abstract: An apparatus and method for beamforming in a communication system are provided, in which a base station receives a channel vector from each of a plurality of mobile stations, generates an uplink channel matrix using the received channel vectors, generates a beamforming weight vector using the uplink channel matrix and a fixed constant that minimizes a channel error rate, and forms beams using the beamforming weight vector.

Abstract: Provided is an apparatus and method for canceling interference by a base station in a wireless mobile communication system. The method includes measuring a state of a channel with a mobile station, determining metric function values for channels that act as interference to the channel of the mobile station, selecting a predetermined number of interference channels in descending order of the metric function values, determining a weight vector for removing a signal transmitted over the interference channels, and applying the determined weight vector to a transmission signal and transmitting the weight vector applied signal.

Abstract: An apparatus and method for allocating radio resources in a wireless communication system are provided, in which a channel variation detector detects channel variations of mobile stations (MSs) using channel information estimated from a sounding channel included in a received signal and a scheduler determines sounding channel allocation periods for the MSs and selects MSs to which the radio resources will be allocated according to the channel variations of the MSs.